Showing 1–50 of 678 results for author: Diaz, A

Coupling nanoscopic tomography and micromagnetic modelling to assess the stability of geomagnetic recorders

Authors: Ualisson Donardelli Bellon, Wyn Williams, Ricardo Ivan Ferreira Trindade, Ana Diaz, Douglas Galante

Abstract: The recording of planetary magnetic fields is often attributed to uniformly-magnetised nanoscopic iron oxides, called single-domain (SD). Yet, the main magnetic constituents of rocks are more complex, non-uniformly magnetised grains in single or multi-vortex states. We know little about their behaviour due to limitations in defining their precise shape and internal magnetic structure. We propose a… ▽ More The recording of planetary magnetic fields is often attributed to uniformly-magnetised nanoscopic iron oxides, called single-domain (SD). Yet, the main magnetic constituents of rocks are more complex, non-uniformly magnetised grains in single or multi-vortex states. We know little about their behaviour due to limitations in defining their precise shape and internal magnetic structure. We propose a novel approach combining non-destructive synchrotron-based ptychographic nanotomography with micromagnetic modelling to explore the magnetic stability of remanence-bearing minerals. Applied to a microscopic rock sample, we identified hundreds of nanoscopic grains of magnetite/maghemite with diverse morphologies. For some grains, shape irregularities near the transition from SD to the single-vortex state allow for multiple domain states, some unstable and unable to record the field for significant periods. Additionally, some other grains exhibit temperature-dependent occupancy probabilities, potentially hampering experiments to recover the intensity of past magnetic fields. △ Less

Submitted 11 April, 2024; originally announced April 2024.

Comments: 23 pages, 8 Figures, 1 Table, 1 Supplementary File

Search for Neutrino Emission from GRB 221009A using the KM3NeT ARCA and ORCA detectors

Authors: S. Aiello, A. Albert, M. Alshamsi, S. Alves Garre, A. Ambrosone, F. Ameli, M. Andre, E. Androutsou, M. Anguita, L. Aphecetche, M. Ardid, S. Ardid, H. Atmani, J. Aublin, F. Badaracco, L. Bailly-Salins, Z. Bardačová, B. Baret, A. Bariego-Quintana, S. Basegmez du Pree, Y. Becherini, M. Bendahman, F. Benfenati, M. Benhassi, D. M. Benoit , et al. (251 additional authors not shown)

Abstract: Gamma-ray bursts are promising candidate sources of high-energy astrophysical neutrinos. The recent GRB 221009A event, identified as the brightest gamma-ray burst ever detected, provides a unique opportunity to investigate hadronic emissions involving neutrinos. The KM3NeT undersea neutrino detectors participated in the worldwide follow-up effort triggered by the event, searching for neutrino even… ▽ More Gamma-ray bursts are promising candidate sources of high-energy astrophysical neutrinos. The recent GRB 221009A event, identified as the brightest gamma-ray burst ever detected, provides a unique opportunity to investigate hadronic emissions involving neutrinos. The KM3NeT undersea neutrino detectors participated in the worldwide follow-up effort triggered by the event, searching for neutrino events. In this letter, we summarize subsequent searches, in a wide energy range from MeV up to a few PeVs. No neutrino events are found in any of the searches performed. Upper limits on the neutrino emission associated with GRB 221009A are computed. △ Less

Submitted 8 April, 2024; originally announced April 2024.

Comments: 10 pages, 2 PDF figures. Submitted to ApJL

Physical properties of circumnuclear ionising clusters. III. Kinematics of gas and stars in NGC 7742

Authors: S. Zamora, A. I. Díaz, Roberto Terlevich, Elena Terlevich, R. Amorín

Abstract: In this third paper of a series, we study the kinematics of the ionised gas and stars, calculating the dynamical masses of the circumnuclear star-forming regions in the ring of of the face-on spiral NGC 7742. We have used high spectral resolution data from the MEGARA instrument attached to the Gran Telescopio Canarias (GTC) to measure the kinematical components of the nebular emission lines of sel… ▽ More In this third paper of a series, we study the kinematics of the ionised gas and stars, calculating the dynamical masses of the circumnuclear star-forming regions in the ring of of the face-on spiral NGC 7742. We have used high spectral resolution data from the MEGARA instrument attached to the Gran Telescopio Canarias (GTC) to measure the kinematical components of the nebular emission lines of selected HII regions and the stellar velocity dispersions from the CaT absorption lines that allow the derivation of the associated cluster virialized masses. The emission line profiles show two different kinematical components: a narrow one with velocity dispersion $\sim$ 10 km/s and a broad one with velocity dispersion similar to those found for the stellar absorption lines. The derived star cluster dynamical masses range from 2.5 $\times$ 10$^6$ to 10.0 $\times$ 10$^7$ M$_\odot$. The comparison of gas and stellar velocity dispersions suggests a scenario where the clusters have formed simultaneously in a first star formation episode with a fraction of the stellar evolution feedback remaining trapped in the cluster, subject to the same gravitational potential as the cluster stars. Between 0.15 and 7.07 % of the total dynamical mass of the cluster would have cooled down and formed a new, younger, population of stars, responsible for the ionisation of the gas currently observed. △ Less

Submitted 4 April, 2024; v1 submitted 2 April, 2024; originally announced April 2024.

Comments: 14 pages, 14 figures, Submitted to Astronomy & Astrophysics

Quantum Magnetic Skyrmion Operator

Authors: Andreas Haller, Sebastián A. Díaz, Wolfgang Belzig, Thomas L. Schmidt

Abstract: We propose a variational wave function to represent quantum skyrmions as bosonic operators. The operator faithfully reproduces two fundamental features of quantum skyrmions: their classical magnetic order and a "quantum cloud" of local spin-flip excitations. Using exact numerical simulations of the ground states of a 2D chiral magnetic model, we find two regions in the single-skyrmion state diagra… ▽ More We propose a variational wave function to represent quantum skyrmions as bosonic operators. The operator faithfully reproduces two fundamental features of quantum skyrmions: their classical magnetic order and a "quantum cloud" of local spin-flip excitations. Using exact numerical simulations of the ground states of a 2D chiral magnetic model, we find two regions in the single-skyrmion state diagram distinguished by their leading quantum corrections. We use matrix product state simulations of the adiabatic braiding of two skyrmions to verify that the operator representation of skyrmions is valid at large inter-skyrmion distances. Our work demonstrates that skyrmions can be approximately coarse-grained and represented by bosonic quasiparticles, which paves the way toward a field theory of many-skyrmion quantum phases and, unlike other approaches, incorporates the microscopic quantum fluctuations of individual skyrmions. △ Less

Submitted 16 April, 2024; v1 submitted 15 March, 2024; originally announced March 2024.

Comments: 9 pages, 4 figures, replaced with revised version

Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

Authors: DUNE Collaboration, A. Abed Abud, B. Abi, R. Acciarri, M. A. Acero, M. R. Adames, G. Adamov, M. Adamowski, D. Adams, M. Adinolfi, C. Adriano, A. Aduszkiewicz, J. Aguilar, B. Aimard, F. Akbar, K. Allison, S. Alonso Monsalve, M. Alrashed, A. Alton, R. Alvarez, T. Alves, H. Amar, P. Amedo, J. Anderson, D. A. Andrade , et al. (1340 additional authors not shown)

Abstract: The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmi… ▽ More The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements, and provide comparisons to detector simulations. △ Less

Submitted 5 March, 2024; originally announced March 2024.

Comments: 47 pages, 41 figures

Report number: FERMILAB-PUB-24-0073-LBNF

Seymour's second neighbourhood conjecture: random graphs and reductions

Authors: Alberto Espuny Díaz, António Girão, Bertille Granet, Gal Kronenberg

Abstract: A longstanding conjecture of Seymour states that in every oriented graph there is a vertex whose second outneighbourhood is at least as large as its outneighbourhood. In this short note we show that, for any fixed $p\in[0,1/2)$, a.a.s. every orientation of $G(n,p)$ satisfies Seymour's conjecture (as well as a related conjecture of Sullivan). This improves on a recent result of Botler, Moura and Na… ▽ More A longstanding conjecture of Seymour states that in every oriented graph there is a vertex whose second outneighbourhood is at least as large as its outneighbourhood. In this short note we show that, for any fixed $p\in[0,1/2)$, a.a.s. every orientation of $G(n,p)$ satisfies Seymour's conjecture (as well as a related conjecture of Sullivan). This improves on a recent result of Botler, Moura and Naia. Moreover, we show that $p=1/2$ is a natural barrier for this problem, in the following sense: for any fixed $p\in(1/2,1)$, Seymour's conjecture is actually equivalent to saying that, with probability bounded away from $0$, every orientation of $G(n,p)$ satisfies Seymour's conjecture. This provides a first reduction of the problem. For a second reduction, we consider minimum degrees and show that, if Seymour's conjecture is false, then there must exist arbitrarily large strongly-connected counterexamples with bounded minimum outdegree. Contrasting this, we show that vertex-minimal counterexamples must have large minimum outdegree. △ Less

Submitted 5 March, 2024; originally announced March 2024.

Comments: 8 pages

Observation of Seven Astrophysical Tau Neutrino Candidates with IceCube

Authors: IceCube Collaboration, R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi , et al. (380 additional authors not shown)

Abstract: We report on a measurement of astrophysical tau neutrinos with 9.7 years of IceCube data. Using convolutional neural networks trained on images derived from simulated events, seven candidate $ν_τ$ events were found with visible energies ranging from roughly 20 TeV to 1 PeV and a median expected parent $ν_τ$ energy of about 200 TeV. Considering backgrounds from astrophysical and atmospheric neutrin… ▽ More We report on a measurement of astrophysical tau neutrinos with 9.7 years of IceCube data. Using convolutional neural networks trained on images derived from simulated events, seven candidate $ν_τ$ events were found with visible energies ranging from roughly 20 TeV to 1 PeV and a median expected parent $ν_τ$ energy of about 200 TeV. Considering backgrounds from astrophysical and atmospheric neutrinos, and muons from $π^\pm/K^\pm$ decays in atmospheric air showers, we obtain a total estimated background of about 0.5 events, dominated by non-$ν_τ$ astrophysical neutrinos. Thus, we rule out the absence of astrophysical $ν_τ$ at the $5σ$ level. The measured astrophysical $ν_τ$ flux is consistent with expectations based on previously published IceCube astrophysical neutrino flux measurements and neutrino oscillations. △ Less

Submitted 26 March, 2024; v1 submitted 4 March, 2024; originally announced March 2024.

Comments: Accepted for publication in Physical Review Letters. This version includes full author list metadata

Improved modeling of in-ice particle showers for IceCube event reconstruction

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, L. Ausborm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, S. Bash, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise , et al. (394 additional authors not shown)

Abstract: The IceCube Neutrino Observatory relies on an array of photomultiplier tubes to detect Cherenkov light produced by charged particles in the South Pole ice. IceCube data analyses depend on an in-depth characterization of the glacial ice, and on novel approaches in event reconstruction that utilize fast approximations of photoelectron yields. Here, a more accurate model is derived for event reconstr… ▽ More The IceCube Neutrino Observatory relies on an array of photomultiplier tubes to detect Cherenkov light produced by charged particles in the South Pole ice. IceCube data analyses depend on an in-depth characterization of the glacial ice, and on novel approaches in event reconstruction that utilize fast approximations of photoelectron yields. Here, a more accurate model is derived for event reconstruction that better captures our current knowledge of ice optical properties. When evaluated on a Monte Carlo simulation set, the median angular resolution for in-ice particle showers improves by over a factor of three compared to a reconstruction based on a simplified model of the ice. The most substantial improvement is obtained when including effects of birefringence due to the polycrystalline structure of the ice. When evaluated on data classified as particle showers in the high-energy starting events sample, a significantly improved description of the events is observed. △ Less

Submitted 22 April, 2024; v1 submitted 4 March, 2024; originally announced March 2024.

Comments: 28 pages, 18 figures, 1 table, submitted to JINST, updated to account for comments received

Characterization of the Astrophysical Diffuse Neutrino Flux using Starting Track Events in IceCube

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, L. Ausborm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, S. Bash, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise , et al. (394 additional authors not shown)

Abstract: A measurement of the diffuse astrophysical neutrino spectrum is presented using IceCube data collected from 2011-2022 (10.3 years). We developed novel detection techniques to search for events with a contained vertex and exiting track induced by muon neutrinos undergoing a charged-current interaction. Searching for these starting track events allows us to not only more effectively reject atmospher… ▽ More A measurement of the diffuse astrophysical neutrino spectrum is presented using IceCube data collected from 2011-2022 (10.3 years). We developed novel detection techniques to search for events with a contained vertex and exiting track induced by muon neutrinos undergoing a charged-current interaction. Searching for these starting track events allows us to not only more effectively reject atmospheric muons but also atmospheric neutrino backgrounds in the southern sky, opening a new window to the sub-100 TeV astrophysical neutrino sky. The event selection is constructed using a dynamic starting track veto and machine learning algorithms. We use this data to measure the astrophysical diffuse flux as a single power law flux (SPL) with a best-fit spectral index of $γ= 2.58 ^{+0.10}_{-0.09}$ and per-flavor normalization of $φ^{\mathrm{Astro}}_{\mathrm{per-flavor}} = 1.68 ^{+0.19}_{-0.22} \times 10^{-18} \times \mathrm{GeV}^{-1} \mathrm{cm}^{-2} \mathrm{s}^{-1} \mathrm{sr}^{-1}$ (at 100 TeV). The sensitive energy range for this dataset is 3 - 550 TeV under the SPL assumption. This data was also used to measure the flux under a broken power law, however we did not find any evidence of a low energy cutoff. △ Less

Submitted 27 February, 2024; originally announced February 2024.

Comments: 27 pages, 28 figures

Results of the follow-up of ANTARES neutrino alerts

Authors: A. Albert, S. Alves, M. André, M. Ardid, S. Ardid, J. -J. Aubert, J. Aublin, B. Baret, S. Basa, Y. Becherini, B. Belhorma, M. Bendahman, F. Benfenati, V. Bertin, S. Biagi, M. Bissinger, J. Boumaaza, M. Bouta, M. C. Bouwhuis, H. Brânzas, R. Bruijn, J. Brunner, J. Busto, B. Caiffi, D. Calvo , et al. (166 additional authors not shown)

Abstract: High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. To look for transient sources associated with neutrino emission, a follow-up program of neutrino alerts has been operating within the ANTARES Collaboration since 2009. This program, named TAToO, has triggered robotic optical telescopes (MASTER, TAROT, ROTSE… ▽ More High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. To look for transient sources associated with neutrino emission, a follow-up program of neutrino alerts has been operating within the ANTARES Collaboration since 2009. This program, named TAToO, has triggered robotic optical telescopes (MASTER, TAROT, ROTSE and the SVOM ground based telescopes) immediately after the detection of any relevant neutrino candidate and scheduled several observations in the weeks following the detection. A subset of ANTARES events with highest probabilities of being of cosmic origin has also been followed by the Swift and the INTEGRAL satellites, the Murchison Widefield Array radio telescope and the H.E.S.S. high-energy gamma-ray telescope. The results of twelve years of observations are reported. No optical counterpart has been significantly associated with an ANTARES candidate neutrino signal during image analysis. Constraints on transient neutrino emission have been set. In September 2015, ANTARES issued a neutrino alert and during the follow-up, a potential transient counterpart was identified by Swift and MASTER. A multi-wavelength follow-up campaign has allowed to identify the nature of this source and has proven its fortuitous association with the neutrino. The return of experience is particularly important for the design of the alert system of KM3NeT, the next generation neutrino telescope in the Mediterranean Sea. △ Less

Submitted 26 February, 2024; originally announced February 2024.

Comments: 27 pages, 14 figures, submitted to JCAP

Astronomy potential of KM3NeT/ARCA

Authors: S. Aiello, A. Albert, M. Alshamsi, S. Alves Garre, Z. Aly, A. Ambrosone, F. Ameli, M. Andre, E. Androutsou, M. Anguita, L. Aphecetche, M. Ardid, S. Ardid, H. Atmani, J. Aublin, F. Badaracco, L. Bailly-Salins, Z. Bardacová, B. Baret, A. Bariego-Quintana, A. Baruzzi, S. Basegmez du Pree, Y. Becherini, M. Bendahman, F. Benfenati , et al. (253 additional authors not shown)

Abstract: The KM3NeT/ARCA neutrino detector is currently under construction at 3500 m depth offshore Capo Passero, Sicily, in the Mediterranean Sea. The main science objectives are the detection of high-energy cosmic neutrinos and the discovery of their sources. Simulations were conducted for the full KM3NeT/ARCA detector, instrumenting a volume of 1 km$^3$, to estimate the sensitivity and discovery potenti… ▽ More The KM3NeT/ARCA neutrino detector is currently under construction at 3500 m depth offshore Capo Passero, Sicily, in the Mediterranean Sea. The main science objectives are the detection of high-energy cosmic neutrinos and the discovery of their sources. Simulations were conducted for the full KM3NeT/ARCA detector, instrumenting a volume of 1 km$^3$, to estimate the sensitivity and discovery potential to point-like neutrino sources and an all-sky diffuse neutrino flux. This paper covers the reconstruction of track- and shower-like signatures, as well as the criteria employed for neutrino event selection. By leveraging both the track and shower observation channels, the KM3NeT/ARCA detector demonstrates the capability to detect the diffuse astrophysical neutrino flux within half a year of operation, achieving a 5$σ$ statistical significance. With an angular resolution below 0.1$^\circ$ for tracks and under 2$^\circ$ for showers, the sensitivity to point-like neutrino sources surpasses existing observed limits across the entire sky. △ Less

Submitted 29 March, 2024; v1 submitted 13 February, 2024; originally announced February 2024.

Comments: 20 pages, 30 figures Submitted to EPJ-C

Doping Liquid Argon with Xenon in ProtoDUNE Single-Phase: Effects on Scintillation Light

Authors: DUNE Collaboration, A. Abed Abud, B. Abi, R. Acciarri, M. A. Acero, M. R. Adames, G. Adamov, M. Adamowski, D. Adams, M. Adinolfi, C. Adriano, A. Aduszkiewicz, J. Aguilar, B. Aimard, F. Akbar, K. Allison, S. Alonso Monsalve, M. Alrashed, A. Alton, R. Alvarez, H. Amar Es-sghir, P. Amedo, J. Anderson, D. A. Andrade, C. Andreopoulos , et al. (1300 additional authors not shown)

Abstract: Doping of liquid argon TPCs (LArTPCs) with a small concentration of xenon is a technique for light-shifting and facilitates the detection of the liquid argon scintillation light. In this paper, we present the results of the first doping test ever performed in a kiloton-scale LArTPC. From February to May 2020, we carried out this special run in the single-phase DUNE Far Detector prototype (ProtoDUN… ▽ More Doping of liquid argon TPCs (LArTPCs) with a small concentration of xenon is a technique for light-shifting and facilitates the detection of the liquid argon scintillation light. In this paper, we present the results of the first doping test ever performed in a kiloton-scale LArTPC. From February to May 2020, we carried out this special run in the single-phase DUNE Far Detector prototype (ProtoDUNE-SP) at CERN, featuring 770 t of total liquid argon mass with 410 t of fiducial mass. The goal of the run was to measure the light and charge response of the detector to the addition of xenon, up to a concentration of 18.8 ppm. The main purpose was to test the possibility for reduction of non-uniformities in light collection, caused by deployment of photon detectors only within the anode planes. Light collection was analysed as a function of the xenon concentration, by using the pre-existing photon detection system (PDS) of ProtoDUNE-SP and an additional smaller set-up installed specifically for this run. In this paper we first summarize our current understanding of the argon-xenon energy transfer process and the impact of the presence of nitrogen in argon with and without xenon dopant. We then describe the key elements of ProtoDUNE-SP and the injection method deployed. Two dedicated photon detectors were able to collect the light produced by xenon and the total light. The ratio of these components was measured to be about 0.65 as 18.8 ppm of xenon were injected. We performed studies of the collection efficiency as a function of the distance between tracks and light detectors, demonstrating enhanced uniformity of response for the anode-mounted PDS. We also show that xenon doping can substantially recover light losses due to contamination of the liquid argon by nitrogen. △ Less

Submitted 9 February, 2024; v1 submitted 2 February, 2024; originally announced February 2024.

Comments: 35 pages, 20 figures

Report number: CERN-EP-2024-024; FERMILAB-PUB-23-0819-LBNF

Developments and applications of the OPTIMADE API for materials discovery, design, and data exchange

Authors: Matthew L. Evans, Johan Bergsma, Andrius Merkys, Casper W. Andersen, Oskar B. Andersson, Daniel Beltrán, Evgeny Blokhin, Tara M. Boland, Rubén Castañeda Balderas, Kamal Choudhary, Alberto Díaz Díaz, Rodrigo Domínguez García, Hagen Eckert, Kristjan Eimre, María Elena Fuentes Montero, Adam M. Krajewski, Jens Jørgen Mortensen, José Manuel Nápoles Duarte, Jacob Pietryga, Ji Qi, Felipe de Jesús Trejo Carrillo, Antanas Vaitkus, Jusong Yu, Adam Zettel, Pedro Baptista de Castro , et al. (34 additional authors not shown)

Abstract: The Open Databases Integration for Materials Design (OPTIMADE) application programming interface (API) empowers users with holistic access to a growing federation of databases, enhancing the accessibility and discoverability of materials and chemical data. Since the first release of the OPTIMADE specification (v1.0), the API has undergone significant development, leading to the upcoming v1.2 relea… ▽ More The Open Databases Integration for Materials Design (OPTIMADE) application programming interface (API) empowers users with holistic access to a growing federation of databases, enhancing the accessibility and discoverability of materials and chemical data. Since the first release of the OPTIMADE specification (v1.0), the API has undergone significant development, leading to the upcoming v1.2 release, and has underpinned multiple scientific studies. In this work, we highlight the latest features of the API format, accompanying software tools, and provide an update on the implementation of OPTIMADE in contributing materials databases. We end by providing several use cases that demonstrate the utility of the OPTIMADE API in materials research that continue to drive its ongoing development. △ Less

Submitted 5 April, 2024; v1 submitted 1 February, 2024; originally announced February 2024.

Growth of hydroxyapatite in a biocompatible mesoporous ordered silica

Authors: A. Diaz, T. Lopez, J. Manjarrez, E. Basaldella, J. M. Martinez-Blanes, J. A. Odriozola

Abstract: A novel biomaterial (HA,SBA15) has been developed based on the growth of calcium phosphate hydroxyapatite (HA) nanoparticles within an organized silica structure (SBA15) A novel biomaterial (HA,SBA15) has been developed based on the growth of calcium phosphate hydroxyapatite (HA) nanoparticles within an organized silica structure (SBA15) △ Less

Submitted 29 January, 2024; originally announced January 2024.

Graded pseudo-H-rings

Authors: Antonio J. Calderón, Antonio Díaz, Marina Haralampidou, José M. Sánchez

Abstract: Consider a pseudo-$H$-space $E$ endowed with a separately continuous biadditive associative multiplication which induces a grading on $E$ with respect to an abelian group $G$. We call such a space a graded pseudo-$H$-ring and we show that it has the form $E = cl(U + \sum_j I_j)$ with $U$ a closed subspace of $E_1$ (the summand associated to the unit element in $G$), and any $I_j$ runs over a well… ▽ More Consider a pseudo-$H$-space $E$ endowed with a separately continuous biadditive associative multiplication which induces a grading on $E$ with respect to an abelian group $G$. We call such a space a graded pseudo-$H$-ring and we show that it has the form $E = cl(U + \sum_j I_j)$ with $U$ a closed subspace of $E_1$ (the summand associated to the unit element in $G$), and any $I_j$ runs over a well described closed graded ideal of $E$, satisfying $I_jI_k = 0$ if $j \neq k$. We also give a context in which graded simplicity of $E$ is characterized. Moreover, the second Wedderburn-type theorem is given for certain graded pseudo-$H$-rings. △ Less

Submitted 23 January, 2024; originally announced January 2024.

Journal ref: Banach Journal of Mathematical Analysis 9 (2015), no. 2, 311-321

Citizen Science for IceCube: Name that Neutrino

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, L. Ausborm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi , et al. (391 additional authors not shown)

Abstract: Name that Neutrino is a citizen science project where volunteers aid in classification of events for the IceCube Neutrino Observatory, an immense particle detector at the geographic South Pole. From March 2023 to September 2023, volunteers did classifications of videos produced from simulated data of both neutrino signal and background interactions. Name that Neutrino obtained more than 128,000 cl… ▽ More Name that Neutrino is a citizen science project where volunteers aid in classification of events for the IceCube Neutrino Observatory, an immense particle detector at the geographic South Pole. From March 2023 to September 2023, volunteers did classifications of videos produced from simulated data of both neutrino signal and background interactions. Name that Neutrino obtained more than 128,000 classifications by over 1,800 registered volunteers that were compared to results obtained by a deep neural network machine-learning algorithm. Possible improvements for both Name that Neutrino and the deep neural network are discussed. △ Less

Submitted 22 January, 2024; originally announced January 2024.

Measurement of Electron Neutrino and Antineutrino Cross Sections at Low Momentum Transfer

Authors: S. Henry, H. Su, S. Akhter, Z. Ahmad Dar, V. Ansari, M. V. Ascencio, M. Sajjad Athar, A. Bashyal, M. Betancourt, J. L. Bonilla, A. Bravar, G. Caceres, G. A. Díaz, J. Felix, L. Fields, R. Fine, P. K. Gaur, S. M. Gilligan, R. Gran, E. Granados, D. A. Harris, A. L. Hart, J. Kleykamp, A. Klustová, M. Kordosky , et al. (31 additional authors not shown)

Abstract: Accelerator based neutrino oscillation experiments seek to measure the relative number of electron and muon neutrinos and antineutrinos at different $L/E$ values. However high statistics studies of neutrino interactions are almost exclusively measured using muon neutrinos and antineutrinos since the dominant flavor of neutrinos produced by accelerator based beams are of the muon type. This work re… ▽ More Accelerator based neutrino oscillation experiments seek to measure the relative number of electron and muon neutrinos and antineutrinos at different $L/E$ values. However high statistics studies of neutrino interactions are almost exclusively measured using muon neutrinos and antineutrinos since the dominant flavor of neutrinos produced by accelerator based beams are of the muon type. This work reports new measurements of electron neutrino and antineutrino interactions in hydrocarbon, obtained by strongly suppressing backgrounds initiated by muon flavor neutrinos and antineutrinos. Double differential cross sections as a function of visible energy transfer, $E_\text{avail}$, and transverse momentum transfer, $p_T$, or three momentum transfer, $q_3$ are presented. △ Less

Submitted 16 April, 2024; v1 submitted 27 December, 2023; originally announced December 2023.

Comments: 25 pages, 32 figures and 7 tables, accepted for publication in Physical Review D. Revised to add content updated in review process

Report number: FERMILAB-PUB-23-0830-PPD

Search for 10--1,000 GeV neutrinos from Gamma Ray Bursts with IceCube

Authors: IceCube Collaboration, R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, L. Ausborm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise , et al. (384 additional authors not shown)

Abstract: We present the results of a search for 10--1,000 GeV neutrinos from 2,268 gamma-ray bursts over 8 years of IceCube-DeepCore data. This work probes burst physics below the photosphere where electromagnetic radiation cannot escape. Neutrinos of tens of GeVs are predicted in sub-photospheric collision of free streaming neutrons with bulk-jet protons. In a first analysis, we searched for the most sign… ▽ More We present the results of a search for 10--1,000 GeV neutrinos from 2,268 gamma-ray bursts over 8 years of IceCube-DeepCore data. This work probes burst physics below the photosphere where electromagnetic radiation cannot escape. Neutrinos of tens of GeVs are predicted in sub-photospheric collision of free streaming neutrons with bulk-jet protons. In a first analysis, we searched for the most significant neutrino-GRB coincidence using six overlapping time windows centered on the prompt phase of each GRB. In a second analysis, we conducted a search for a group of GRBs, each individually too weak to be detectable, but potentially significant when combined. No evidence of neutrino emission is found for either analysis. The most significant neutrino coincidence is for Fermi-GBM GRB bn 140807500, with a p-value of 0.097 corrected for all trials. The binomial test used to search for a group of GRBs had a p-value of 0.65 after all trial corrections. The binomial test found a group consisting only of GRB bn 140807500 and no additional GRBs. The neutrino limits of this work complement those obtained by IceCube at TeV to PeV energies. We compare our findings for the large set of GRBs as well as GRB 221009A to the sub-photospheric neutron-proton collision model and find that GRB 221009A provides the most constraining limit on baryon loading. For a jet Lorentz factor of 300 (800), the baryon loading on GRB 221009A is lower than 3.85 (2.13) at a 90% confidence level. △ Less

Submitted 29 March, 2024; v1 submitted 12 December, 2023; originally announced December 2023.

Journal ref: ApJ 964 126 (2024)

All-Sky Search for Transient Astrophysical Neutrino Emission with 10 Years of IceCube Cascade Events

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, L. Ausborm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi , et al. (382 additional authors not shown)

Abstract: We present the results of a time-dependent search for neutrino flares in data collected by IceCube between May 2011 and 2021. This data set contains cascade-like events originating from charged-current electron neutrino and tau neutrino interactions and all-flavor neutral-current interactions. IceCube's previous all-sky searches for neutrino flares used data sets consisting of track-like events or… ▽ More We present the results of a time-dependent search for neutrino flares in data collected by IceCube between May 2011 and 2021. This data set contains cascade-like events originating from charged-current electron neutrino and tau neutrino interactions and all-flavor neutral-current interactions. IceCube's previous all-sky searches for neutrino flares used data sets consisting of track-like events originating from charged-current muon neutrino interactions. The cascade data sets are statistically independent of the track data sets and provide a new opportunity to observe the transient all-sky landscape. This search uses the spatial, temporal, and energy information of the cascade-like events to conduct searches for the most statistically significant neutrino flares in the northern and southern skies. No statistically significant time-dependent neutrino emission was observed. For the most statistically significant location in the northern sky, $p_\mathrm{global} =$ 0.71, and in the southern sky, $p_\mathrm{global} =$ 0.51. These results are compatible with the background hypothesis. Assuming an E$^{-2.53}$ spectrum from the diffuse astrophysical neutrino flux as measured with cascades, these results are used to calculate upper limits at the 90\% confidence level on neutrino flares of varying duration and constrain the contribution of these flares to the diffuse astrophysical neutrino flux. These constraints are independent of a specified class of astrophysical objects and show that multiple unresolved transient sources may contribute to the diffuse astrophysical neutrino flux. △ Less

Submitted 11 March, 2024; v1 submitted 8 December, 2023; originally announced December 2023.

Comments: Submitted to The Astrophysical Journal

The DUNE Far Detector Vertical Drift Technology, Technical Design Report

Authors: DUNE Collaboration, A. Abed Abud, B. Abi, R. Acciarri, M. A. Acero, M. R. Adames, G. Adamov, M. Adamowski, D. Adams, M. Adinolfi, C. Adriano, A. Aduszkiewicz, J. Aguilar, B. Aimard, F. Akbar, K. Allison, S. Alonso Monsalve, M. Alrashed, A. Alton, R. Alvarez, H. Amar, P. Amedo, J. Anderson, D. A. Andrade, C. Andreopoulos , et al. (1304 additional authors not shown)

Abstract: DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precisi… ▽ More DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals. △ Less

Submitted 5 December, 2023; originally announced December 2023.

Comments: 425 pages; 281 figures Central editing team: A. Heavey, S. Kettell, A. Marchionni, S. Palestini, S. Rajogopalan, R. J. Wilson

Report number: Fermilab Report no: TM-2813-LBNF

Nonlinear-manifold reduced order models with domain decomposition

Authors: Alejandro N. Diaz, Youngsoo Choi, Matthias Heinkenschloss

Abstract: A nonlinear-manifold reduced order model (NM-ROM) is a great way of incorporating underlying physics principles into a neural network-based data-driven approach. We combine NM-ROMs with domain decomposition (DD) for efficient computation. NM-ROMs offer benefits over linear-subspace ROMs (LS-ROMs) but can be costly to train due to parameter scaling with the full-order model (FOM) size. To address t… ▽ More A nonlinear-manifold reduced order model (NM-ROM) is a great way of incorporating underlying physics principles into a neural network-based data-driven approach. We combine NM-ROMs with domain decomposition (DD) for efficient computation. NM-ROMs offer benefits over linear-subspace ROMs (LS-ROMs) but can be costly to train due to parameter scaling with the full-order model (FOM) size. To address this, we employ DD on the FOM, compute subdomain NM-ROMs, and then merge them into a global NM-ROM. This approach has multiple advantages: parallel training of subdomain NM-ROMs, fewer parameters than global NM-ROMs, and adaptability to subdomain-specific FOM features. Each subdomain NM-ROM uses a shallow, sparse autoencoder, enabling hyper-reduction (HR) for improved computational speed. In this paper, we detail an algebraic DD formulation for the FOM, train HR-equipped NM-ROMs for subdomains, and numerically compare them to DD LS-ROMs with HR. Results show a significant accuracy boost, on the order of magnitude, for the proposed DD NM-ROMs over DD LS-ROMs in solving the 2D steady-state Burgers' equation. △ Less

Submitted 1 December, 2023; originally announced December 2023.

Comments: To be included in the proceedings of the Machine Learning and the Physical Sciences Workshop at NeurIPS 2023. arXiv admin note: text overlap with arXiv:2305.15163

Report number: LLNL-CONF-854737

Functionalized carbophenes as high-capacity versatile gas adsorbents: An ab initio study

Authors: Chad E. Junkermeier, Evan Larmand, Jean-Charles Morais, Jedediah Kobebel, Kat Lavarez, R. Martin Adra, Jirui Yang, Valeria Aparicio Diaz, Ricardo Paupitz, George Psofogiannakis

Abstract: This study employs density functional theory (DFT) and density functional tight-binding theory (DFTB) to determine the adsorption properties of carbon dioxide (CO$_2$), methane (CH$_4$), and dihydrogen (H$_2$) in carbophenes functionalized with carboxyl (COOH), amine (NH$_2$), nitro (NO$_2$), and hydroxyl (OH) groups. We demonstrate that carbophenes are promising candidates as adsorbents for these… ▽ More This study employs density functional theory (DFT) and density functional tight-binding theory (DFTB) to determine the adsorption properties of carbon dioxide (CO$_2$), methane (CH$_4$), and dihydrogen (H$_2$) in carbophenes functionalized with carboxyl (COOH), amine (NH$_2$), nitro (NO$_2$), and hydroxyl (OH) groups. We demonstrate that carbophenes are promising candidates as adsorbents for these gasses. Carbophenes have larger CO$_2$ and CH$_4$ adsorption energies than other next-generation solid-state capture materials. Yet, the low predicted desorption temperatures mean they can be beneficial as air scrubbers in confined spaces. Functionalized carbophenes have H$_2$ adsorption energies usually observed in metal-containing materials. Further, the predicted desorption temperatures of H$_2$ from carbophenes lie within the DOE Technical Targets for Onboard Hydrogen Storage for Light-Duty Vehicles (DOEHST) operating temperature range. The possibility of tailoring the degree of functionalization in combination with selecting sufficiently open carbophene structures that allow for multiple strong interactions without steric hindrance (crowding) effects, added to the multiplicity of possible functional groups alone or in combination, suggests that these very light materials can be ideal adsorbates for many gases. Tailoring the design to specific adsorption or separation needs would require extensive combinatorial investigations. △ Less

Submitted 29 November, 2023; originally announced November 2023.

Journal ref: Computational Materials Science 232 (2024) 112665

The Power Board of the KM3NeT Digital Optical Module: design, upgrade, and production

Authors: S. Aiello, A. Albert, S. Alves Garre, Z. Aly, A. Ambrosone, F. Ameli, M. Andre, E. Androutsou, M. Anguita, L. Aphecetche, M. Ardid, S. Ardid, H. Atmani, J. Aublin, F. Badaracco, L. Bailly-Salins, Z. Bardacova, B. Baret, A. Bariego Quintana, S. Basegmez du Pree, Y. Becherini, M. Bendahman, F. Benfenati, M. Benhassi, D. M. Benoit , et al. (259 additional authors not shown)

Abstract: The KM3NeT Collaboration is building an underwater neutrino observatory at the bottom of the Mediterranean Sea consisting of two neutrino telescopes, both composed of a three-dimensional array of light detectors, known as digital optical modules. Each digital optical module contains a set of 31 three inch photomultiplier tubes distributed over the surface of a 0.44 m diameter pressure-resistant gl… ▽ More The KM3NeT Collaboration is building an underwater neutrino observatory at the bottom of the Mediterranean Sea consisting of two neutrino telescopes, both composed of a three-dimensional array of light detectors, known as digital optical modules. Each digital optical module contains a set of 31 three inch photomultiplier tubes distributed over the surface of a 0.44 m diameter pressure-resistant glass sphere. The module includes also calibration instruments and electronics for power, readout and data acquisition. The power board was developed to supply power to all the elements of the digital optical module. The design of the power board began in 2013, and several prototypes were produced and tested. After an exhaustive validation process in various laboratories within the KM3NeT Collaboration, a mass production batch began, resulting in the construction of over 1200 power boards so far. These boards were integrated in the digital optical modules that have already been produced and deployed, 828 until October 2023. In 2017, an upgrade of the power board, to increase reliability and efficiency, was initiated. After the validation of a pre-production series, a production batch of 800 upgraded boards is currently underway. This paper describes the design, architecture, upgrade, validation, and production of the power board, including the reliability studies and tests conducted to ensure the safe operation at the bottom of the Mediterranean Sea throughout the observatory's lifespan △ Less

Submitted 24 November, 2023; originally announced November 2023.

JetLOV: Enhancing Jet Tree Tagging through Neural Network Learning of Optimal LundNet Variables

Authors: Mauricio A. Diaz, Giorgio Cerro, Jacan Chaplais, Srinandan Dasmahapatra, Stefano Moretti

Abstract: Machine learning has played a pivotal role in advancing physics, with deep learning notably contributing to solving complex classification problems such as jet tagging in the field of jet physics. In this experiment, we aim to harness the full potential of neural networks while acknowledging that, at times, we may lose sight of the underlying physics governing these models. Nevertheless, we demons… ▽ More Machine learning has played a pivotal role in advancing physics, with deep learning notably contributing to solving complex classification problems such as jet tagging in the field of jet physics. In this experiment, we aim to harness the full potential of neural networks while acknowledging that, at times, we may lose sight of the underlying physics governing these models. Nevertheless, we demonstrate that we can achieve remarkable results obscuring physics knowledge and relying completely on the model's outcome. We introduce JetLOV, a composite comprising two models: a straightforward multilayer perceptron (MLP) and the well-established LundNet. Our study reveals that we can attain comparable jet tagging performance without relying on the pre-computed LundNet variables. Instead, we allow the network to autonomously learn an entirely new set of variables, devoid of a priori knowledge of the underlying physics. These findings hold promise, particularly in addressing the issue of model dependence, which can be mitigated through generalization and training on diverse data sets. △ Less

Submitted 24 November, 2023; originally announced November 2023.

Comments: Accepted at the NeurIPS 2023 workshop: Machine Learning and the Physical Sciences

Searches for neutrino counterparts of gravitational waves from the LIGO/Virgo third observing run with KM3NeT

Authors: KM3NeT Collaboration, S. Aiello, A. Albert, S. Alves Garre, Z. Aly, A. Ambrosone, F. Ameli, M. Andre, E. Androutsou, M. Anguita, L. Aphecetche, M. Ardid, S. Ardid, H. Atmani, J. Aublin, L. Bailly-Salins, Z. Bardačová, B. Baret, A. Bariego-Quintana, S. Basegmez du Pree, Y. Becherini, M. Bendahman, F. Benfenati, M. Benhassi, D. M. Benoit , et al. (251 additional authors not shown)

Abstract: The KM3NeT neutrino telescope is currently being deployed at two different sites in the Mediterranean Sea. First searches for astrophysical neutrinos have been performed using data taken with the partial detector configuration already in operation. The paper presents the results of two independent searches for neutrinos from compact binary mergers detected during the third observing run of the LIG… ▽ More The KM3NeT neutrino telescope is currently being deployed at two different sites in the Mediterranean Sea. First searches for astrophysical neutrinos have been performed using data taken with the partial detector configuration already in operation. The paper presents the results of two independent searches for neutrinos from compact binary mergers detected during the third observing run of the LIGO and Virgo gravitational wave interferometers. The first search looks for a global increase in the detector counting rates that could be associated with inverse beta decay events generated by MeV-scale electron anti-neutrinos. The second one focuses on upgoing track-like events mainly induced by muon (anti-)neutrinos in the GeV--TeV energy range. Both searches yield no significant excess for the sources in the gravitational wave catalogs. For each source, upper limits on the neutrino flux and on the total energy emitted in neutrinos in the respective energy ranges have been set. Stacking analyses of binary black hole mergers and neutron star-black hole mergers have also been performed to constrain the characteristic neutrino emission from these categories. △ Less

Submitted 7 November, 2023; originally announced November 2023.

Comments: 19 pages, 11 figures

Chemical evolution models: the role of type Ia supernovae in the $α$-elements over Iron relative abundances and their variations in time and space

Authors: M. Mollá, O. Cavichia, J. J. Bazán, A. Castrillo, L. Galbany, I. Millán-Irigoyen, Y. Ascasibar. A. I Díaz

Abstract: The role of type Ia supernovae, mainly the Delay Time Distributions (DTDs) determined by the binary systems, and the yields of elements created by different explosion mechanisms, are studied by using the {\sc MulChem} chemical evolution model, applied to our Galaxy. We explored 15 DTDs, and 12 tables of elemental yields produced by different SN Ia explosion mechanisms, doing a total of 180 models.… ▽ More The role of type Ia supernovae, mainly the Delay Time Distributions (DTDs) determined by the binary systems, and the yields of elements created by different explosion mechanisms, are studied by using the {\sc MulChem} chemical evolution model, applied to our Galaxy. We explored 15 DTDs, and 12 tables of elemental yields produced by different SN Ia explosion mechanisms, doing a total of 180 models. Chemical abundances for $α$-elements (O, Mg, Si, S, Ca) and Fe derived from these models, are compared with recent observational data of $α$-elements over Iron relative abundances, [X/Fe]. These data have been compiled and binned in 13 datasets. By using a $χ^2$-technique, no model is able to fit simultaneously these datasets. A model computed with the 13 individual best models is good enough to reproduce them. Thus, a power law with a logarithmic slope $\sim -1.1$ and a delay in the range $Δτ=40 --350$ Myr is a possible DTD, but a combination of several channels is more probable. Results of this average model for other disc regions show a high dispersion, as observed, which might be explained by the stellar migration. The dispersion might also come from a combination of DTDs or of explosion channels. The stellar migration joined to a combination of scenarios for SNIa is the probable cause of the observed dispersion. △ Less

Submitted 31 October, 2023; originally announced November 2023.

Comments: submitted to MNRAS as main tex and appendix, here we send the whole text in 31 pages, by including Appendix that will be as Supporting Information in the publication

Surface Second Harmonic Generation in Centrosymmetric Molecular Crystalline Materials: How Thick is the Surface?

Authors: Benedikt Zerulla, Alejandro Luna Díaz, Christof Holzer, Carsten Rockstuhl, Ivan Fernandez-Corbaton, Marjan Krstić

Abstract: Second harmonic generation (SHG) is forbidden in centrosymmetric molecular materials. However, a signal is frequently observed from interfaces where the symmetry is broken. Whereas the effect can be phenomenologically accommodated, an ab initio qualitative and quantitative description has remained elusive, preventing the exploration of fascinating questions such as how deep below the surface the s… ▽ More Second harmonic generation (SHG) is forbidden in centrosymmetric molecular materials. However, a signal is frequently observed from interfaces where the symmetry is broken. Whereas the effect can be phenomenologically accommodated, an ab initio qualitative and quantitative description has remained elusive, preventing the exploration of fascinating questions such as how deep below the surface the second harmonic can still be generated. To answer such questions, we present an ab initio multiscale approach to compute the total and layer-dependent intensity of surface SHG from molecular crystals. The microscopic origin of surface SHG is identified in layer-dependent models with embedding partial charges combined with density functional theory. The models show increasing symmetry-breaking distortions of the electron cloud around the molecules as the surface layer is approached. The SHG at the molecular level is determined using time-dependent density functional theory and then brought to the scale of macroscopic films through a rigorous self-consistent multiple scattering formalism capable of predicting the measurable optical intensities of the generated second harmonic signal. We study crystalline molecular films with centrosymmetric unit cells of 7,9-Dibromobenzo[h]quinolin-10-ol. The intensity of the SHG at the surface layer is two orders of magnitude larger than at the next layer below and three orders of magnitude larger than two layers below. Besides providing fundamental understanding, our approach can be used for designing and optimizing optical devices containing nonlinear molecular materials, such as molecular laminates. We show that a relatively basic Kretschmann-like setup can enhance the surface SHG of a crystalline film of centrosymmetric molecular unit cells a thousand times. △ Less

Submitted 11 January, 2024; v1 submitted 31 October, 2023; originally announced October 2023.

Comments: 12 pages, 6 figures

Measurement of the Multi-Neutron $\barν_μ$ Charged Current Differential Cross Section at Low Available Energy on Hydrocarbon

Authors: A. Olivier, T. Cai, S. Akhter, Z. Ahmad Dar, V. Ansari, M. V. Ascencio, M. Sajjad Athar, A. Bashyal, A. Bercellie, M. Betancourt, J. L. Bonilla, A. Bravar, H. Budd, G. Caceres, G. A. Díaz, J. Felix, L. Fields, A. Filkins, R. Fine, A. M. Gago, P. K. Gaur, S. M. Gilligan, R. Gran, E. Granados, D. A. Harris , et al. (36 additional authors not shown)

Abstract: Neutron production in antineutrino interactions can lead to bias in energy reconstruction in neutrino oscillation experiments, but these interactions have rarely been studied. MINERvA previously studied neutron production at an average antineutrino energy of ~3 GeV in 2016 and found deficiencies in leading models. In this paper, the MINERvA 6 GeV average antineutrino energy data set is shown to ha… ▽ More Neutron production in antineutrino interactions can lead to bias in energy reconstruction in neutrino oscillation experiments, but these interactions have rarely been studied. MINERvA previously studied neutron production at an average antineutrino energy of ~3 GeV in 2016 and found deficiencies in leading models. In this paper, the MINERvA 6 GeV average antineutrino energy data set is shown to have similar disagreements. A measurement of the cross section for an antineutrino to produce two or more neutrons and have low visible energy is presented as an experiment-independent way to explore neutron production modeling. This cross section disagrees with several leading models' predictions. Neutron modeling techniques from nuclear physics are used to quantify neutron detection uncertainties on this result. △ Less

Submitted 21 November, 2023; v1 submitted 25 October, 2023; originally announced October 2023.

Comments: 25 pages, 11 figures; Added ancillary files with cross section values as .csv Matches preprint accepted by publisher

Report number: PUB-23-610-ND

Physical properties of circumnuclear ionising clusters. II. NGC 7469

Authors: S. Zamora, Ángeles I. Díaz

Abstract: Circumnuclear star forming regions (CNSFR) are massive clusters found close to galactic nuclei. These entities give us an excellent opportunity to study star formation in environments with high metallicity and to relate it with active galactic nuclei. Our principal aim is to derive the physical properties and dynamical masses of the CNSFRs in the two rings of the spiral NGC 7469, categorized as a… ▽ More Circumnuclear star forming regions (CNSFR) are massive clusters found close to galactic nuclei. These entities give us an excellent opportunity to study star formation in environments with high metallicity and to relate it with active galactic nuclei. Our principal aim is to derive the physical properties and dynamical masses of the CNSFRs in the two rings of the spiral NGC 7469, categorized as a Luminous Infrared Galaxy (ULIRG) and hosting a Seyfert 1 nucleus. We have used archival data obtained with the MUSE spectrograph attached to one of the ESO VLT telescopes and we have applied the techniques shown in the first paper of the series. Regions in the studied galaxy show large sizes which can be explained by the stellar winds produced by WR stars. The inner ring regions seem to be more compact than the outer ones, showing higher electron densities and filling factors. The young stellar population of the clusters has contributions of ionising populations with ages around 5 Ma and its masses constitute less than a 1\% of the total mass of each cluster. The inner ring regions which are close to the active galactic nucleus probably are the only ones that have enough mass to survive the action of the AGN. They constitute the $\sim$ 90 \% of the total inner ring mass. △ Less

Submitted 19 October, 2023; originally announced October 2023.

Comments: 22 pages, 25 figures, Submitted to Astronomy & Astrophysics

Manipulating Vortices with Domain Walls in Superconductor-Ferromagnet Heterostructures

Authors: Sebastián A. Díaz, Jonas Nothhelfer, Kjetil M. D. Hals, Karin Everschor-Sitte

Abstract: Vortices are point-like topological defects in superconductors whose motion dictates superconducting properties and controls device performance. In superconductor-ferromagnet heterostructures, vortices interact with topological defects in the ferromagnet such as line-like domain walls. While in previous heterostructure generations, vortex-domain wall interactions were mediated by stray fields; in… ▽ More Vortices are point-like topological defects in superconductors whose motion dictates superconducting properties and controls device performance. In superconductor-ferromagnet heterostructures, vortices interact with topological defects in the ferromagnet such as line-like domain walls. While in previous heterostructure generations, vortex-domain wall interactions were mediated by stray fields; in new heterostructure families, more important become exchange fields and spin-orbit coupling. However, spin-orbit coupling's role in vortex-domain wall interactions remains unexplored. Here we uncover, via numerical simulations and Ginzburg-Landau theory, that Rashba spin-orbit coupling induces magnetoelectric interactions between vortices and domain walls that crucially depend on the wall's winding direction$-$its helicity. The wall's helicity controls whether vortices are pushed or dragged by Néel walls, and their gliding direction along Bloch walls. Our work capitalizes on interactions between topological defects from different order parameters and of different dimensionality to engineer enhanced functionality. △ Less

Submitted 5 October, 2023; originally announced October 2023.

Comments: 10 pages, 5 figures

Revising the cross correlation technique at high spectral resolution

Authors: S. Zamora, A. I. Díaz

Abstract: Cross-correlation techniques have been used since 1974 for measuring velocity shifts and velocity dispersions from stellar and nebular spectra and, since 1979, the analysis based on the Fourier Method has been applied. However, we are currently obtaining data with spectral resolutions higher than those for which this technique was developed, hence some revision seems timely. The principal aim of t… ▽ More Cross-correlation techniques have been used since 1974 for measuring velocity shifts and velocity dispersions from stellar and nebular spectra and, since 1979, the analysis based on the Fourier Method has been applied. However, we are currently obtaining data with spectral resolutions higher than those for which this technique was developed, hence some revision seems timely. The principal aim of this work is adapting Tonry and Davis' method and implementing it for the treatment of very high spectral resolution data. We have applied this technique to two different sets of spectroscopic data of moderate and high resolutions obtained with the MUSE and MEGARA spectrographs respectively. Using stellar spectra obtained with these two instruments (i) we have optimised the input parameters; (ii) we have analysed the method assumptions; and (iii) we have compared the results for the two sets of data. For MEGARA data, we have found that the cross-correlation function lost its Gaussian behavior at higher resolutions. Thus, we have developed an equivalent mathematical method that can be used for this kind of data. Additionally, the velocity dispersion error analysis suggests that the greatest error introduced in this method is due to the subtraction or masking of the nebular lines. For the application of cross-correlation techniques to high spectral resolution data, we propose to calculate the galaxy-galaxy and star-galaxy correlations, with widths $μ_{gg}$ and $μ_{gt}$ respectively. Then, the width of the broadening function can be calculated as $σ= \sqrt{μ_{gg}^2 - μ_{gt}^2}$. △ Less

Submitted 27 March, 2024; v1 submitted 6 October, 2023; originally announced October 2023.

Comments: 10 pages, 11 figures, Submitted to MNRAS;

Experimental and theoretical assessment of native oxide in the superconducting TaN

Authors: V. Quintanar-Zamora, M. Cedillo-Rosillo, O. Contreras-López, C. Corona-García, A. Reyes-Serrato, R. Ponce-Pérez, J. Guerrero-Sánchez, J. A. Díaz

Abstract: In this manuscript, we show through an experimental-computational proof of concept the native oxide formation into superconducting TaN films. First, TaN was synthesized at an ultra-high vacuum system by reactive pulsed laser deposition and characterized in situ by X-ray photoelectron spectroscopy. The material was also characterized ex situ by X-ray diffraction, transmission electron microscopy, a… ▽ More In this manuscript, we show through an experimental-computational proof of concept the native oxide formation into superconducting TaN films. First, TaN was synthesized at an ultra-high vacuum system by reactive pulsed laser deposition and characterized in situ by X-ray photoelectron spectroscopy. The material was also characterized ex situ by X-ray diffraction, transmission electron microscopy, and the four-point probe method. It was detected that TaN contained considerable oxygen impurities (up to 26 %O) even though it was grown in an ultra-high vacuum chamber. Furthermore, the impurified TaN evidence a face-centered cubic crystalline structure only and exhibits superconductivity at 2.99 K. To understand the feasibility of the native oxide in TaN, we study the effect of incorporating different amounts of O atoms in TaN using ab-initio calculations. A thermodynamic stability analysis shows that a TaOxN1-x model increases its stability as oxygen is added, demonstrating that oxygen may always be present in TaN, even when obtained at ultra-high vacuum conditions. All analyzed models exhibit metallic behavior. Charge density difference maps reveal that N and O atoms have a higher charge density redistribution than Ta atoms. The electron localization function maps and line profiles indicate that Ta-O and Ta-N bonds are mainly ionic. As expected, stronger ionic behavior is observed in the Ta-O bonds due to the electronegativity difference between O and N atoms. Recent evidence points to superconductivity in bulk TaO, confirming the asseverations of superconductivity in our samples. The results discussed here highlight the importance of considering native oxide when reporting superconductivity in TaN films since the TaO regions formed in the compound may be key to understanding the different critical temperatures reported in the literature. △ Less

Submitted 21 September, 2023; originally announced September 2023.

Comments: 23 pages, 7 figures

Search for Continuous and Transient Neutrino Emission Associated with IceCube's Highest-Energy Tracks: An 11-Year Analysis

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, L. Ausborm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi , et al. (385 additional authors not shown)

Abstract: IceCube alert events are neutrinos with a moderate-to-high probability of having astrophysical origin. In this study, we analyze 11 years of IceCube data and investigate 122 alert events and a selection of high-energy tracks detected between 2009 and the end of 2021. This high-energy event selection (alert events + high-energy tracks) has an average probability of $\geq 0.5$ to be of astrophysical… ▽ More IceCube alert events are neutrinos with a moderate-to-high probability of having astrophysical origin. In this study, we analyze 11 years of IceCube data and investigate 122 alert events and a selection of high-energy tracks detected between 2009 and the end of 2021. This high-energy event selection (alert events + high-energy tracks) has an average probability of $\geq 0.5$ to be of astrophysical origin. We search for additional continuous and transient neutrino emission within the high-energy events' error regions. We find no evidence for significant continuous neutrino emission from any of the alert event directions. The only locally significant neutrino emission is the transient emission associated with the blazar TXS~0506+056, with a local significance of $ 3 σ$, which confirms previous IceCube studies. When correcting for 122 test positions, the global p-value is $0.156$ and is compatible with the background hypothesis. We constrain the total continuous flux emitted from all 122 test positions at 100~TeV to be below $1.2 \times 10^{-15}$~(TeV cm$^2$ s)$^{-1}$ at 90% confidence assuming an $E^{-2}$ spectrum. This corresponds to 4.5% of IceCube's astrophysical diffuse flux. Overall, we find no indication that alert events, in general, are linked to lower-energetic continuous or transient neutrino emission. △ Less

Submitted 5 February, 2024; v1 submitted 21 September, 2023; originally announced September 2023.

Comments: Accepted by ApJ

Journal ref: 2024 ApJ 964 40

Searches for neutrinos in the direction of radio-bright blazars with the ANTARES telescope

Authors: ANTARES Collaboration, A. Albert, S. Alves, M. André, M. Ardid, S. Ardid, J. J. Aubert, J Aublin, B. Baret, S. Basa, Y. Becherini, B. Belhorma, M. Bendahman, F. Benfenati, V. Bertin, S. Biagi, M. Bissinger, J. Boumaaza, M. Bouta, M. C. Bouwhuis, H. Brânzaş, R. Bruijn, J. Brunner, J. Busto, B. Caiffi , et al. (140 additional authors not shown)

Abstract: Active galaxies, especially blazars, are among the most promising neutrino source candidates. To date, ANTARES searches for these objects considered GeV-TeV $γ$-ray bright blazars. Here, a statistically complete radio-bright blazar sample is used as the target for searches of origins of neutrinos collected by the ANTARES neutrino telescope over 13 years of operation. The hypothesis of a neutrino-b… ▽ More Active galaxies, especially blazars, are among the most promising neutrino source candidates. To date, ANTARES searches for these objects considered GeV-TeV $γ$-ray bright blazars. Here, a statistically complete radio-bright blazar sample is used as the target for searches of origins of neutrinos collected by the ANTARES neutrino telescope over 13 years of operation. The hypothesis of a neutrino-blazar directional correlation is tested by pair counting and by a complementary likelihood-based approach. The resulting post-trial $p$-value is $3.0\%$ ($2.2σ$ in the two-sided convention), possibly indicating a correlation. Additionally, a time-dependent analysis is performed to search for temporal clustering of neutrino candidates as a mean of detecting neutrino flares in blazars. None of the investigated sources alone reaches a significant flare detection level. However, the presence of 18 sources with a pre-trial significance above $3σ$ indicates a $p=1.4\%$ ($2.5σ$ in the two-sided convention) detection of a time-variable neutrino flux. An \textit{a posteriori} investigation reveals an intriguing temporal coincidence of neutrino, radio, and $γ$-ray flares of the J0242+1101 blazar at a $p=0.5\%$ ($2.9σ$ in the two-sided convention) level. Altogether, the results presented here suggest a possible connection of neutrino candidates detected by the ANTARES telescope with radio-bright blazars. △ Less

Submitted 13 September, 2023; originally announced September 2023.

Journal ref: ApJ 964 (2024) 3

LHC Study of Third-Generation Scalar Leptoquarks with Machine-Learned Likelihoods

Authors: Ernesto Arganda, Daniel A. Díaz, Andres D. Perez, Rosa M. Sandá Seoane, Alejandro Szynkman

Abstract: We study the impact of machine-learning algorithms on LHC searches for leptoquarks in final states with hadronically decaying tau leptons, multiple $b$-jets, and large missing transverse momentum. Pair production of scalar leptoquarks with decays only into third-generation leptons and quarks is assumed. Thanks to the use of supervised learning tools with unbinned methods to handle the high-dimensi… ▽ More We study the impact of machine-learning algorithms on LHC searches for leptoquarks in final states with hadronically decaying tau leptons, multiple $b$-jets, and large missing transverse momentum. Pair production of scalar leptoquarks with decays only into third-generation leptons and quarks is assumed. Thanks to the use of supervised learning tools with unbinned methods to handle the high-dimensional final states, we consider simple selection cuts which would possibly translate into an improvement in the exclusion limits at the 95$\%$ confidence level for leptoquark masses with different values of their branching fraction into charged leptons. In particular, for intermediate branching fractions, we expect that the exclusion limits for leptoquark masses extend to $\sim$1.3 TeV. As a novelty in the implemented unbinned analysis, we include a simplified estimation of some systematic uncertainties with the aim of studying their possible impact on the stability of the results. Finally, we also present the projected sensitivity within this framework at 14 TeV for 300 and 3000 fb$^{-1}$ that extends the upper limits to $\sim$1.6 and $\sim$1.8 TeV, respectively. △ Less

Submitted 11 March, 2024; v1 submitted 11 September, 2023; originally announced September 2023.

Comments: 25 pages, 7 figures, 2 tables (version published in PRD). Unbinned method code with approach to systematic uncertainty inclusion available from https://github.com/AndresDanielPerez/

Report number: IFT-UAM/CSIC-23-110

Prospects for combined analyses of hadronic emission from $γ$-ray sources in the Milky Way with CTA and KM3NeT

Authors: T. Unbehaun, L. Mohrmann, S. Funk, S. Aiello, A. Albert, S. Alves Garre, Z. Aly, A. Ambrosone, F. Ameli, M. Andre, E. Androutsou, M. Anghinolfi, M. Anguita, L. Aphecetche, M. Ardid, S. Ardid, H. Atmani, J. Aublin, C. Bagatelas, L. Bailly-Salins, Z. Bardačová, B. Baret, S. Basegmez du Pree, Y. Becherini, M. Bendahman , et al. (249 additional authors not shown)

Abstract: The Cherenkov Telescope Array and the KM3NeT neutrino telescopes are major upcoming facilities in the fields of $γ$-ray and neutrino astronomy, respectively. Possible simultaneous production of $γ$ rays and neutrinos in astrophysical accelerators of cosmic-ray nuclei motivates a combination of their data. We assess the potential of a combined analysis of CTA and KM3NeT data to determine the contri… ▽ More The Cherenkov Telescope Array and the KM3NeT neutrino telescopes are major upcoming facilities in the fields of $γ$-ray and neutrino astronomy, respectively. Possible simultaneous production of $γ$ rays and neutrinos in astrophysical accelerators of cosmic-ray nuclei motivates a combination of their data. We assess the potential of a combined analysis of CTA and KM3NeT data to determine the contribution of hadronic emission processes in known Galactic $γ$-ray emitters, comparing this result to the cases of two separate analyses. In doing so, we demonstrate the capability of Gammapy, an open-source software package for the analysis of $γ$-ray data, to also process data from neutrino telescopes. For a selection of prototypical $γ$-ray sources within our Galaxy, we obtain models for primary proton and electron spectra in the hadronic and leptonic emission scenario, respectively, by fitting published $γ$-ray spectra. Using these models and instrument response functions for both detectors, we employ the Gammapy package to generate pseudo data sets, where we assume 200 hours of CTA observations and 10 years of KM3NeT detector operation. We then apply a three-dimensional binned likelihood analysis to these data sets, separately for each instrument and jointly for both. We find that the largest benefit of the combined analysis lies in the possibility of a consistent modelling of the $γ$-ray and neutrino emission. Assuming a purely leptonic scenario as input, we obtain, for the most favourable source, an average expected 68% credible interval that constrains the contribution of hadronic processes to the observed $γ$-ray emission to below 15%. △ Less

Submitted 2 February, 2024; v1 submitted 6 September, 2023; originally announced September 2023.

Comments: 20 pages, 16 figures. v2: Matches version published in EPJC

Journal ref: European Physical Journal C 84, 112 (2024)

Testing Meson Portal Dark Sector Solutions to the MiniBooNE Anomaly at CCM

Authors: A. A. Aguilar-Arevalo, S. Biedron, J. Boissevain, M. Borrego, L. Bugel, M. Chavez-Estrada, J. M. Conrad, R. L. Cooper, A. Diaz, J. R. Distel, J. C. D'Olivo, E. Dunton, B. Dutta, D. Fields, J. R. Gochanour, M. Gold, E. Guardincerri, E. C. Huang, N. Kamp, D. Kim, K. Knickerbocker, W. C. Louis, J. T. M. Lyles, R. Mahapatra, S. Maludze , et al. (20 additional authors not shown)

Abstract: A solution to the MiniBooNE excess invoking rare three-body decays of the charged pions and kaons to new states in the MeV mass scale was recently proposed as a dark-sector explanation. This class of solution illuminates the fact that, while the charged pions were focused in the target-mode run, their decay products were isotropically suppressed in the beam-dump-mode run in which no excess was obs… ▽ More A solution to the MiniBooNE excess invoking rare three-body decays of the charged pions and kaons to new states in the MeV mass scale was recently proposed as a dark-sector explanation. This class of solution illuminates the fact that, while the charged pions were focused in the target-mode run, their decay products were isotropically suppressed in the beam-dump-mode run in which no excess was observed. This suggests a new physics solution correlated to the mesonic sector. We investigate an extended set of phenomenological models that can explain the MiniBooNE excess as a dark sector solution, utilizing long-lived particles that might be produced in the three-body decays of the charged mesons and the two-body anomalous decays of the neutral mesons. Over a broad set of interactions with the long-lived particles, we show that these scenarios can be compatible with constraints from LSND, KARMEN, and MicroBooNE, and evaluate the sensitivity of the ongoing and future data taken by the Coherent CAPTAIN Mills experiment (CCM) to a potential discovery in this parameter space. △ Less

Submitted 22 March, 2024; v1 submitted 5 September, 2023; originally announced September 2023.

Comments: Corrected calculation mistake in Eq. 11. Revised sections for submission to PRD

Report number: LA-UR-23-29529

Unveiling the evolutionary state of three B supergiant stars: PU Gem, $ε$ CMa and $η$ CMa

Authors: Julieta P. Sánchez Arias, Péter Németh, Elisson S. G. de Almeida, Matias A. Ruiz Diaz, Michaela Kraus, Maximiliano Haucke

Abstract: We aim to combine asteroseismology, spectroscopy, and evolutionary models to establish a comprehensive picture of the evolution of Galactic blue supergiant stars (BSG). To start such an investigation, we selected three BSG candidates for our analysis: HD 42087 (PU Gem), HD 52089 ($ε$ CMa) and HD 58350 ($η$ CMa). These stars show pulsations and were suspected to be in an evolutionary stage either p… ▽ More We aim to combine asteroseismology, spectroscopy, and evolutionary models to establish a comprehensive picture of the evolution of Galactic blue supergiant stars (BSG). To start such an investigation, we selected three BSG candidates for our analysis: HD 42087 (PU Gem), HD 52089 ($ε$ CMa) and HD 58350 ($η$ CMa). These stars show pulsations and were suspected to be in an evolutionary stage either preceding or succeding the red supergiant (RSG) stage. For our analysis, we utilized the 2-min cadence TESS data to study the photometric variability and obtained new spectroscopic observations at the CASLEO observatory. We calculated CMFGEN non-LTE radiative transfer models and derived stellar and wind parameters using the iterative spectral analysis pipeline XTGRID. The spectral modeling was limited to changing only the effective temperature, surface gravity, CNO abundances, and mass-loss rates. Finally, we compared the derived metal abundances with predictions from Geneva stellar evolution models. The frequency spectra of all three stars show either stochastic oscillations, nonradial strange modes, or a rotational splitting. We conclude that the rather short sectoral observing windows of TESS prevent establishing a reliable mode identification of low frequencies connected to mass-loss variabilities. The spectral analysis confirmed gradual changes in the mass-loss rates and the derived CNO abundances comply with the values reported in the literature. We were able to achieve a quantitative match with stellar evolution models for the stellar masses and luminosities. However, the spectroscopic surface abundances turned out to be inconsistent with theoretical predictions. The stars show N enrichment, typical for CNO cycle processed material, but the abundance ratios do not reflect the associated levels of C and O depletion. △ Less

Submitted 24 August, 2023; originally announced August 2023.

Comments: 29 pages, 18 figures, Accepted for publication in Galaxies

Embedded Software of the KM3NeT Central Logic Board

Authors: S. Aiello, A. Albert, S. Alves Garre, Z. Aly, A. Ambrosone, F. Ameli, M. Andre, E. Androutsou, M. Anghinolfi, M. Anguita, L. Aphecetche, M. Ardid, S. Ardid, H. Atmani, J. Aublin, C. Bagatelas, L. Bailly-Salins, Z. Bardačová, B. Baret, S. Basegmez du Pree, Y. Becherini, M. Bendahman, F. Benfenati, M. Benhassi, D. M. Benoit , et al. (249 additional authors not shown)

Abstract: The KM3NeT Collaboration is building and operating two deep sea neutrino telescopes at the bottom of the Mediterranean Sea. The telescopes consist of latices of photomultiplier tubes housed in pressure-resistant glass spheres, called digital optical modules and arranged in vertical detection units. The two main scientific goals are the determination of the neutrino mass ordering and the discovery… ▽ More The KM3NeT Collaboration is building and operating two deep sea neutrino telescopes at the bottom of the Mediterranean Sea. The telescopes consist of latices of photomultiplier tubes housed in pressure-resistant glass spheres, called digital optical modules and arranged in vertical detection units. The two main scientific goals are the determination of the neutrino mass ordering and the discovery and observation of high-energy neutrino sources in the Universe. Neutrinos are detected via the Cherenkov light, which is induced by charged particles originated in neutrino interactions. The photomultiplier tubes convert the Cherenkov light into electrical signals that are acquired and timestamped by the acquisition electronics. Each optical module houses the acquisition electronics for collecting and timestamping the photomultiplier signals with one nanosecond accuracy. Once finished, the two telescopes will have installed more than six thousand optical acquisition nodes, completing one of the more complex networks in the world in terms of operation and synchronization. The embedded software running in the acquisition nodes has been designed to provide a framework that will operate with different hardware versions and functionalities. The hardware will not be accessible once in operation, which complicates the embedded software architecture. The embedded software provides a set of tools to facilitate remote manageability of the deployed hardware, including safe reconfiguration of the firmware. This paper presents the architecture and the techniques, methods and implementation of the embedded software running in the acquisition nodes of the KM3NeT neutrino telescopes. △ Less

Submitted 12 October, 2023; v1 submitted 2 August, 2023; originally announced August 2023.

Searching for Decoherence from Quantum Gravity at the IceCube South Pole Neutrino Observatory

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi, C. Benning , et al. (380 additional authors not shown)

Abstract: Neutrino oscillations at the highest energies and longest baselines provide a natural quantum interferometer with which to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, there is a generic expectation that its fluctuations at the Planck scale would introduce non-unitary effects that are inc… ▽ More Neutrino oscillations at the highest energies and longest baselines provide a natural quantum interferometer with which to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, there is a generic expectation that its fluctuations at the Planck scale would introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavor composition at long distances and high energies. The IceCube South Pole Neutrino Observatory is a billion-ton neutrino telescope situated in the deep ice of the Antarctic glacier. Atmospheric neutrinos detected by IceCube in the energy range 0.5--10 TeV have been used to test for coherence loss in neutrino propagation. No evidence of anomalous neutrino decoherence was observed, leading to the strongest experimental limits on neutrino-quantum gravity interactions to date, significantly surpassing expectations from natural Planck-scale models. The resulting constraint on the effective decoherence strength parameter within an energy-independent decoherence model is $Γ_0\leq 1.17\times10^{-15}$~eV, improving upon past limits by a factor of 30. For decoherence effects scaling as E$^2$, limits are advanced by more than six orders of magnitude beyond past measurements. △ Less

Submitted 25 July, 2023; originally announced August 2023.

The IceCube-Gen2 Collaboration -- Contributions to the 38th International Cosmic Ray Conference (ICRC2023)

Authors: IceCube-Gen2, :, R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, J. Audehm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. Becker Tjus, J. Beise , et al. (432 additional authors not shown)

Abstract: IceCube-Gen2 is a planned next-generation neutrino observatory at the South Pole that builds upon the successful design of IceCube. Integrating two complementary detection technologies for neutrinos, optical and radio Cherenkov emission, in combination with a surface array for cosmic ray air shower detection, IceCube-Gen2 will cover a broad neutrino energy range from MeV to EeV. This index of cont… ▽ More IceCube-Gen2 is a planned next-generation neutrino observatory at the South Pole that builds upon the successful design of IceCube. Integrating two complementary detection technologies for neutrinos, optical and radio Cherenkov emission, in combination with a surface array for cosmic ray air shower detection, IceCube-Gen2 will cover a broad neutrino energy range from MeV to EeV. This index of contributions to the 38th International Cosmic Ray Conference in Nagoya, Japan (July 26 - August 3, 2023) describes research and development efforts for IceCube-Gen2. Included are summaries of the design, status, and sensitivity of the IceCube-Gen2 optical, surface, and radio components; performance studies of next-generation optical sensors detecting optical Cherenkov radiation from cosmic ray and neutrino events; reconstruction techniques of radio and optical events in terms of energy, direction, and neutrino flavor; and sensitivity studies of astrophysical neutrino flavors, diffuse neutrino fluxes, and cosmic ray anisotropies. Contributions related to IceCube and the scheduled IceCube Upgrade are available in a separate collection. △ Less

Submitted 24 July, 2023; originally announced July 2023.

Comments: To access the list of contributions, please follow the "HTML" link. Links to individual contributions will fill in as authors upload their material

The IceCube Collaboration -- Contributions to the 38th International Cosmic Ray Conference (ICRC2023)

Authors: IceCube, :, R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise , et al. (382 additional authors not shown)

Abstract: The IceCube Observatory at the South Pole has been operating in its full configuration since May 2011 with a duty cycle of about 99%. Its main component consists of a cubic-kilometer array of optical sensors deployed deep in the Glacial ice designed for the detection of high-energy astrophysical neutrinos. A surface array for cosmic ray air shower detection, IceTop, and a denser inner subdetector,… ▽ More The IceCube Observatory at the South Pole has been operating in its full configuration since May 2011 with a duty cycle of about 99%. Its main component consists of a cubic-kilometer array of optical sensors deployed deep in the Glacial ice designed for the detection of high-energy astrophysical neutrinos. A surface array for cosmic ray air shower detection, IceTop, and a denser inner subdetector, DeepCore, significantly enhance the capabilities of the observatory, making it a multipurpose facility. This list of contributions to the 38th International Cosmic Ray Conference in Nagoya, Japan (July 26 - August 3, 2023) summarizes the latest results from IceCube covering a broad set of key questions in physics and astrophysics. The papers in this index are grouped topically to highlight IceCube contributions related to high-energy neutrino and multi-messenger astrophysics, cosmic-ray physics, low-energy neutrino transients such as Galactic supernovae, fundamental physics, detector calibration and event reconstruction, education and public outreach, and research and development for the IceCube Upgrade, a scheduled dense sensor infill complemented by calibration devices. Contributions related to IceCube-Gen2, the future extension of IceCube, are available in a separate collection. △ Less

Submitted 24 July, 2023; originally announced July 2023.

Comments: To access the list of contributions, please follow the "HTML" link. Links to individual contributions will fill in as authors upload their material

Search for Extended Sources of Neutrino Emission in the Galactic Plane with IceCube

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi, C. Benning , et al. (383 additional authors not shown)

Abstract: The Galactic plane, harboring a diffuse neutrino flux, is a particularly interesting target to study potential cosmic-ray acceleration sites. Recent gamma-ray observations by HAWC and LHAASO have presented evidence for multiple Galactic sources that exhibit a spatially extended morphology and have energy spectra continuing beyond 100 TeV. A fraction of such emission could be produced by interactio… ▽ More The Galactic plane, harboring a diffuse neutrino flux, is a particularly interesting target to study potential cosmic-ray acceleration sites. Recent gamma-ray observations by HAWC and LHAASO have presented evidence for multiple Galactic sources that exhibit a spatially extended morphology and have energy spectra continuing beyond 100 TeV. A fraction of such emission could be produced by interactions of accelerated hadronic cosmic rays, resulting in an excess of high-energy neutrinos clustered near these regions. Using 10 years of IceCube data comprising track-like events that originate from charged-current muon neutrino interactions, we perform a dedicated search for extended neutrino sources in the Galaxy. We find no evidence for time-integrated neutrino emission from the potential extended sources studied in the Galactic plane. The most significant location, at 2.6$σ$ post-trials, is a 1.7$^\circ$ sized region coincident with the unidentified TeV gamma-ray source 3HWC J1951+266. We provide strong constraints on hadronic emission from several regions in the Galaxy. △ Less

Submitted 7 September, 2023; v1 submitted 14 July, 2023; originally announced July 2023.

Comments: 13 pages, 4 figures, 5 tables including an appendix. Accepted for publication in Astrophysical Journal

Journal ref: ApJ 956 20 (2023)

Physical properties of circumnuclear ionising clusters. I. NGC 7742

Authors: S. Zamora, A. I. Díaz

Abstract: This work aims to derive the physical properties of the CNSFRs in the ring of the face-on spiral NGC 7742 using IFS observations. We have selected 88 individual ionising clusters that power HII regions populating the ring of the galaxy that may have originated in a minor merger event. For the HII regions the rate of Lyman continuum photon emission is between 0.025 and 1.5 10$^{51}$ which points to… ▽ More This work aims to derive the physical properties of the CNSFRs in the ring of the face-on spiral NGC 7742 using IFS observations. We have selected 88 individual ionising clusters that power HII regions populating the ring of the galaxy that may have originated in a minor merger event. For the HII regions the rate of Lyman continuum photon emission is between 0.025 and 1.5 10$^{51}$ which points to these regions being ionised by star clusters. Their electron density, ionisation parameter, filling factor and ionised hydrogen mass show values consistent with those found in other studies of similar regions and their metal abundances as traced by sulphur have been found to be between 0.25 and 2.4 times solar, with most regions showing values slightly below solar. The equivalent temperature of the ionising clusters is relatively low, below 40000 K which is consistent with the high elemental abundances derived. The young stellar population of the clusters has contributions of ionising and non-ionising populations with ages around 5 Ma and 300 Ma respectively. The masses of ionising clusters once corrected for the contribution of underlying non-ionising populations were found to have a mean value of 3.5 $\times$ 10$^4$ M$_{\odot}$, comparable to the mass of ionised gas and about 20 \% of the corrected photometric mass. △ Less

Submitted 10 July, 2023; originally announced July 2023.

Comments: 23 pages, 21 figures, accepted for publication in MNRAS;

Observation of high-energy neutrinos from the Galactic plane

Authors: R. Abbasi, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, J. M. Alameddine, A. A. Alves Jr., N. M. Amin, K. Andeen, T. Anderson, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. Axani, X. Bai, A. Balagopal V., S. W. Barwick, V. Basu, S. Baur, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus , et al. (364 additional authors not shown)

Abstract: The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, has been a mystery for over a century. Due to deflection in interstellar magnetic fields, cosmic rays from the Milky Way arrive at Earth from random directions. However, near their sources and during propagation, cosmic rays interact with matter and produce high-energy neutrinos. We search for neutrin… ▽ More The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, has been a mystery for over a century. Due to deflection in interstellar magnetic fields, cosmic rays from the Milky Way arrive at Earth from random directions. However, near their sources and during propagation, cosmic rays interact with matter and produce high-energy neutrinos. We search for neutrino emission using machine learning techniques applied to ten years of data from the IceCube Neutrino Observatory. We identify neutrino emission from the Galactic plane at the 4.5$σ$ level of significance, by comparing diffuse emission models to a background-only hypothesis. The signal is consistent with modeled diffuse emission from the Galactic plane, but could also arise from a population of unresolved point sources. △ Less

Submitted 10 July, 2023; originally announced July 2023.

Comments: Submitted on May 12th, 2022; Accepted on May 4th, 2023

Journal ref: Science 380, 6652, 1338-1343 (2023)

Hard X-ray grazing incidence ptychography: Large field-of-view nanostructure imaging with ultra-high surface sensitivity

Authors: P. S. Jørgensen, L. Besley, A. M. Slyamov, A. Diaz, M. Guizar-Sicairos, M. Odstrcil, M. Holler, C. Silvestre, B. Chang, C. Detlefs, J. W. Andreasen

Abstract: We demonstrate a technique that allows highly surface sensitive imaging of nanostructures on planar surfaces over large areas, providing a new avenue for research in materials science, especially for \textit{in situ} applications. The capabilities of hard X-ray grazing incidence ptychography combine aspects from imaging, reflectometry and grazing incidence small angle scattering in providing large… ▽ More We demonstrate a technique that allows highly surface sensitive imaging of nanostructures on planar surfaces over large areas, providing a new avenue for research in materials science, especially for \textit{in situ} applications. The capabilities of hard X-ray grazing incidence ptychography combine aspects from imaging, reflectometry and grazing incidence small angle scattering in providing large field-of-view images with high resolution transverse to the beam, horizontally and along the surface normal. Thus, it yields data with resolutions approaching electron microscopy, in two dimensions, but over much larger areas and with a poorer resolution in the third spatial dimension, along the beam propagation direction. Similar to grazing incidence small angle X-ray scattering, this technique facilitates the characterization of nanostructures across statistically significant surface areas or volumes within potentially feasible time frames for \textit{in situ} experiments, while also providing spatial information. △ Less

Submitted 4 July, 2023; originally announced July 2023.

Comments: 8 pages, 6 figures

A fast and accurate domain-decomposition nonlinear manifold reduced order model

Authors: Alejandro N. Diaz, Youngsoo Choi, Matthias Heinkenschloss

Abstract: This paper integrates nonlinear-manifold reduced order models (NM-ROMs) with domain decomposition (DD). NM-ROMs approximate the full order model (FOM) state in a nonlinear-manifold by training a shallow, sparse autoencoder using FOM snapshot data. These NM-ROMs can be advantageous over linear-subspace ROMs (LS-ROMs) for problems with slowly decaying Kolmogorov n-width. However, the number of NM-RO… ▽ More This paper integrates nonlinear-manifold reduced order models (NM-ROMs) with domain decomposition (DD). NM-ROMs approximate the full order model (FOM) state in a nonlinear-manifold by training a shallow, sparse autoencoder using FOM snapshot data. These NM-ROMs can be advantageous over linear-subspace ROMs (LS-ROMs) for problems with slowly decaying Kolmogorov n-width. However, the number of NM-ROM parameters that need to be trained scales with the size of the FOM. Moreover, for "extreme-scale" problems, the storage of high-dimensional FOM snapshots alone can make ROM training expensive. To alleviate the training cost, this paper applies DD to the FOM, computes NM-ROMs on each subdomain, and couples them to obtain a global NM-ROM. This approach has several advantages: Subdomain NM-ROMs can be trained in parallel, involve fewer parameters to be trained than global NM-ROMs, require smaller subdomain FOM dimensional training data, and can be tailored to subdomain-specific features of the FOM. The shallow, sparse architecture of the autoencoder used in each subdomain NM-ROM allows application of hyper-reduction (HR), reducing the complexity caused by nonlinearity and yielding computational speedup of the NM-ROM. This paper provides the first application of NM-ROM (with HR) to a DD problem. In particular, this paper details an algebraic DD reformulation of the FOM, training a NM-ROM with HR for each subdomain, and a sequential quadratic programming (SQP) solver to evaluate the coupled global NM-ROM. Theoretical convergence results for the SQP method and a priori and a posteriori error estimates for the DD NM-ROM with HR are provided. The proposed DD NM-ROM with HR approach is numerically compared to a DD LS-ROM with HR on the 2D steady-state Burgers' equation, showing an order of magnitude improvement in accuracy of the proposed DD NM-ROM over the DD LS-ROM. △ Less

Submitted 25 February, 2024; v1 submitted 24 May, 2023; originally announced May 2023.

Report number: LLNL-JRNL-849457

Spacetime magnetic hopfions: from internal excitations and braiding of skyrmions

Authors: R. Knapman, T. Tausendpfund, S. A. Díaz, K. Everschor-Sitte

Abstract: Spatial topology endows topological solitons, such as skyrmions and hopfions, with fascinating dynamics. However, the temporal dimension has so far provided a passive stage on which topological solitons evolve. Here we construct spacetime magnetic hopfions: magnetic textures in two spatial dimensions that when excited by a time-periodic drive develop spacetime topology. We uncover two complementar… ▽ More Spatial topology endows topological solitons, such as skyrmions and hopfions, with fascinating dynamics. However, the temporal dimension has so far provided a passive stage on which topological solitons evolve. Here we construct spacetime magnetic hopfions: magnetic textures in two spatial dimensions that when excited by a time-periodic drive develop spacetime topology. We uncover two complementary construction routes using skyrmions by braiding their center of mass position and by controlling their internal low-energy excitations. Spacetime magnetic hopfions can be realized in nanopatterned grids to braid skyrmions and in frustrated magnets under an applied AC electric field. Their topological invariant, the spacetime Hopf index, can be tuned by the applied electric field as demonstrated by our collective coordinate modeling and micromagnetic simulations. The principles we have introduced to actively control spacetime topology are not limited to magnetic solitons, opening avenues to explore spacetime topology of general order parameters and fields. △ Less

Submitted 12 May, 2023; originally announced May 2023.

High-resolution three-dimensional imaging of topological textures in single-diamond networks

Authors: Dmitry Karpov, Kenza Djeghdi, Mirko Holler, S. Narjes Abdollahi, Karolina Godlewska, Claire Donnelly, Takeshi Yuasa, Hiroaki Sai, Ulrich B. Wiesner, Bodo D. Wilts, Ullrich Steiner, Michimasa Musya, Shunsuke Fukami, Hideo Ohno, Ilja Gunkel, Ana Diaz, Justin Llandro

Abstract: Highly periodic structures are often said to convey the beauty of nature. However, most material properties are strongly influenced by the defects they contain. On the mesoscopic scale, molecular self-assembly exemplifies this interplay; thermodynamic principles determine short-range order, but long-range order is mainly impeded by the kinetic history of the material and by thermal fluctuations. F… ▽ More Highly periodic structures are often said to convey the beauty of nature. However, most material properties are strongly influenced by the defects they contain. On the mesoscopic scale, molecular self-assembly exemplifies this interplay; thermodynamic principles determine short-range order, but long-range order is mainly impeded by the kinetic history of the material and by thermal fluctuations. For the development of self-assembly technologies, it is imperative to characterise and understand the interplay between self-assembled order and defect-induced disorder. Here we used synchrotron-based hard X-ray nanotomography to reveal a pair of extended topological defects within a self-assembled single-diamond network morphology. These defects are morphologically similar to the comet and trefoil patterns of equal and opposite half-integer topological charges observed in liquid crystals and appear to maintain a constant separation across the thickness of the sample, resembling pairs of full vortices in superconductors and other hard condensed matter systems. These results are expected to open new windows to study defect formation in soft condensed matter, particularly in biological systems where most structures are formed by self-assembly. △ Less

Submitted 28 April, 2023; originally announced April 2023.

Search for correlations of high-energy neutrinos detected in IceCube with radio-bright AGN and gamma-ray emission from blazars

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus, J. Beise, C. Bellenghi , et al. (379 additional authors not shown)

Abstract: The IceCube Neutrino Observatory sends realtime neutrino alerts with high probability of being astrophysical in origin. We present a new method to correlate these events and possible candidate sources using $2,089$ blazars from the Fermi-LAT 4LAC-DR2 catalog and with $3,413$ AGNs from the Radio Fundamental Catalog. No statistically significant neutrino emission was found in any of the catalog sear… ▽ More The IceCube Neutrino Observatory sends realtime neutrino alerts with high probability of being astrophysical in origin. We present a new method to correlate these events and possible candidate sources using $2,089$ blazars from the Fermi-LAT 4LAC-DR2 catalog and with $3,413$ AGNs from the Radio Fundamental Catalog. No statistically significant neutrino emission was found in any of the catalog searches. The result is compatible with a small fraction, $<1$%, of AGNs being neutrino emitters and prior evidence for neutrino emission presented by IceCube and other authors from sources such as TXS 0506+056 and PKS 1502+06. We also present cross-checks to other analyses that claim a significant correlation using similar data samples, and we find that adding more information on the neutrino events and more data overall makes the result compatible with background. △ Less

Submitted 25 April, 2023; originally announced April 2023.